Protein kinase activity-dependent inhibition of urokinase-type plasminogen activator gene transcription by cyclic AMP in human pre-B lymphoma cell line RC-K8

We investigated the effects of cAMP on the urokinase-type plasminogen activator (uPA) production in human pre-B lymphoma cell line RC-K8 that is consistently secreting uPA in the conditioned medium. Both Bt2cAMP and PGE1 inhibited the uPA accumulation in a dose-dependent manner. Northern blot analysis and nuclear run-on assay revealed that uPA gene transcription was repressed by Bt2cAMP and the repression was negated by inhibition of de novo protein synthesis by cycloheximide. Pretreatment with H89 (N-[2-(p-bromocinnamyl-amino) ethyl]-5-isoquinoline sulfonamide), a specific cAMP-dependent protein kinase (PKA) inhibitor, strongly inhibited both the PKA activation and the supression of uPA mRNA accumulation induced by cAMP. H85 (N-[2-(N-formyl-p-chlorocinnamyl-amino) ethyl]-5-isoquinoline sulfonamide), which closely resembles H89 in its chemical structure but is not a selective inhibitor of PKA, showed little effect on the regulation of uPA gene regulation by Bt2cAMP. These results suggest that cAMP represses uPA gene transcription in human pre-B lymphoma cells through PKA pathway and in which de novo protein synthesis is required.

Transcriptional regulation of tissue- and urokinase-type plasminogen activator genes by thrombin in human fetal lung fibroblasts

The mechanism of thrombin induction of tissue- and urokinase-type plasminogen activator (t-PA and u-PA) biosynthesis was investigated in cultured human fetal lung fibroblast cells, IMR-90. Northern blot analysis of total RNA from thrombin-treated cells showed marked accumulations of both t-PA and u-PA mRNA during 24 h. Nuclear run-on experiments showed that the transcription rates of both genes were increased in the thrombin-treated cells. These thrombin effects were inhibited by cycloheximide (CHX), an inhibitor of protein biosynthesis. Treatment of IMR-90 cells with CHX alone caused an increase in u-PA mRNA but not in t-PA mRNA. CHX, however, did not affect the transcription rates of both genes in the cells. Thus, on-going protein synthesis is required for increased accumulations of both t-PA and u-PA mRNA by thrombin but not for the constitutive expression of u-PA gene in IMR-90 cells. Therefore, we conclude that the accumulations of t-PA and u-PA mRNA due to thrombin result mainly from increased rates of their gene transcriptions, and that this influence is exerted in part by proteins synthesized by thrombin stimulation. Thrombin also increased plasminogen activator inhibitor type-1 (PAI-1) in the levels of both antigen and mRNA more rapidly than it increased t-PA in IMR-90 cells. In conditioned medium, most of the secreted PAI-1 seemed to form a complex with t-PA. Northern blot analysis using a PAI-2 cDNA probe showed that the levels of PAI-2 mRNA were markedly increased in response to thrombin.(ABSTRACT TRUNCATED AT 250 WORDS)

Carbazochrome sodium sulphonate (AC-17) decreases the accumulation of tissue-type plasminogen activator in culture medium of human umbilical vein endothelial cells

This study investigated the effect of carbazochrome sodium sulphonate (AC-17) on the accumulation of tissue-type plasminogen activator antigen (t-PA:Ag) and plasminogen activator inhibitor-1 antigen (PAI-1:Ag) in culture medium of human umbilical vein endothelial cells (HUVEC). HUVEC were cultured in the presence of AC-17, and the concentration of t-PA:Ag and PAI-1:Ag in the medium was measured by an enzyme-linked immunoassay. AC-17, after 48 and 72 h incubation, significantly decreased the t-PA:Ag in the culture medium, while it had no significant effect on the PAI-1:Ag. The result of fibrin zymography was consistent with the result obtained by ELISA. It also revealed that all of the t-PA present in the culture medium formed complexes with PAI-1, indicating that AC-17 did not interfere with t-PA/PAI-1 complex formation. Furthermore, AC-17 did not inhibit the activities of t-PA and plasmin when measured by a fibrin plate method. These results suggest that AC-17 may modulate the fibrinolytic balance of blood through changing the function of endothelial cells, a new aspect of action of AC-17 as a haemostatic drug.

MRI in neurofibromatosis type I: using fluid-attenuated inversion recovery pulse sequences

Cranial magnetic resonance imaging results of 14 patients with neurofibromatosis type I were examined with T2-weighted fluid-attenuated inversion recovery pulse sequences, as well as conventional T2-weighted spin-echo sequences. Definition was better in 62 of 79 lesions or groups of lesions on fluid-attenuated inversion recovery images than on T2-weighted spin-echo images. The lesions were demonstrated not only in the brainstem, cerebellum, globus pallidus, and cerebral white matter, but also in the hippocampus, pulvinar thalami, and splenium of the corpus callosum. The latter 3 lesions have not been demonstrated or emphasized in previous studies. It is concluded that fluid-attenuated inversion recovery imaging is more effective in detecting multiple lesions in patients with neurofibromatosis type I than conventional T2-weighted spin-echo imaging.

Immunostaining of human amniotic epithelial cells: possible use as a transgene carrier in gene therapy for inborn errors of metabolism

Immunoreactivity of human cultured amniotic epithelial (AE) cells was investigated to evaluate the possible use of these cells as a transgene carrier in gene therapy for inborn errors of metabolism. AE cells were prepared and cultured by the methods described previously. Flow cytometry analysis revealed that these cells did not express any class II antigen at all on their surfaces. But the class I antigen was slightly expressed on their surfaces. Immunoperoxidase staining was slightly positive as to the class I antigen but not to the class II antigen at all. pSV-beta-galactosidase was transfected into AE cells by means of electroporation, followed by staining of the cells with X-gal. Several cells in 60 mm dish expressed beta-galactosidase activity. The possible gene transfer of beta-galactosidase into cultured AE cells may suggest that these cells could be used as a transgene carrier in gene therapy for inborn errors of metabolism.

Improved simple generation of GTG-band specific painting probes

We developed an improved, simple method of generating chromosome-region-specific probes from only a few microdissected chromosomes. One to five dissected fragments from a defined chromosomal region were processed with a PEG/proteinase K cycling deproteinization step and directly amplified with a two-step amplification system using a degenerate oligonucleotide primed shuttle polymerase chain reaction (DOP-Shuttle-PCR). This modified method offered three advantages over previously reported methods: relaxation of the highly condensed chromosomal DNA, reduction of the risk of endogenous and exogenous contamination, and high efficiency amplification of template DNA. High intensity in the fluorescence in situ hybridization (FISH) signals from normal metaphase chromosomes, as well as regional specificity of these probes, corresponding to regions on R-banded chromosomes, were observed.

Vermis lesions in acute cerebellar ataxia: a sequential imaging study

We report a case of acute cerebellar ataxia (ACA) with discrete paleocerebellar clinical symptoms who underwent serial cranial magnetic resonance images not only with conventional spin echo sequences but also fluid attenuated inversion recovery (FLAIR) sequences. The images with the latter sequences demonstrated more conspicuously the high signal intensity lesions in the superior cerebellar vermis and cerebellar peduncle than those with the former sequences. In the convalescent phase, the lesions became markedly atrophic. Thus, the causative lesions for ACA were demonstrated on MRI, and FLAIR provided clear images of the lesion in the vermis.

Ellagic acid/phospholipid-induced coagulation and dextran sulfate-induced fibrinolytic activities in beta 2-glycoprotein I-depleted plasma

Beta 2-glycoprotein I (beta 2-GPI) binds negatively charged substances and inhibits intrinsic blood coagulation in the presence of ellagic acid-phospholipid suspension. Beta 2-GPI is thought to be an important protein in the reaction between negatively charged phospholipids and anti-phospholipid antibodies which appear in patients with lupus anticoagulant/antiphospholipid antibody syndrome. We prepared a monoclonal antibody against beta 2-GPI purified from human plasma and obtained beta 2-GPI-depleted plasma using a monoclonal antibody-coupled column. Either partial thromboplastin time or the activation of prekallikrein induced by diluted ellagic acid-phospholipid suspension in beta 2-GPI-depleted plasma was not different from that in control plasma. Beta 2-GPI inhibited the intrinsic blood coagulation only when added to control or beta 2-GPI-depleted plasma in excess (more than physiological concentrations). The intrinsic fibrinolysis in beta 2-GPI-depleted plasma induced by dextran sulfate was not impaired and, again, beta 2-GPI inhibited the intrinsic fibrinolysis only when added to control or beta 2-GPI-depleted plasma in excess. These results indicate that both in vitro Actin-induced intrinsic coagulation and dextran sulfate-induced fibrinolytic activities are significantly inhibited by more than physiological concentrations of beta 2-GPI.

Hypoproduction of erythropoietin contributes to anemia in chronic cadmium intoxication: clinical study on Itai-itai disease in Japan

Itai-itai disease is a condition caused by long-term exposure of the inhabitants of Toyama prefecture, Japan, to cadmium intoxication. The characteristic clinical features of this disease include renal tubular dysfunction, osteomalacia, and anemia. In order to clarify the pathogenesis of the anemia, the red blood cell count, hemoglobin concentration, hematocrit, serum iron level, total iron-binding capacity, serum ferritin level, serum erythropoietin level, creatinine clearance, fractional excretion of beta 2-microglobulin, and bone marrow morphology were determined in ten patients with Itai-itai disease. Low serum iron or ferritin levels were not observed, and bone marrow aspiration did not reveal any specific hematological disorders. A close relationship was observed between the decrease in the hemoglobin level and the progression of renal dysfunction. Low serum erythropoietin levels were detected despite the presence of severe anemia. These results suggest an important role of renal damage in the anemia which develops in Itai-itai disease.

Niemann-Pick disease: coupling and uncoupling of inhibited sphingomyelinase activity and exogenous cholesterol esterification in fibroblasts by ionophore treatment

In order to elucidate a biochemical relationship between sphingomyelin and cholesterol metabolisms, we examined the effects of several ionophores (monensin, nigericin, A23187, ionomycin, lasalocid) on sphingomyelinase activity and cholesterol esterification in cultured human fibroblasts. Phase-contrast microscopy showed the presence of foamy cells with monensin and nigericin treatments only. Electron microscopic examination revealed lamellated membranous bodies and cytoplasmic vacuoles in cells treated with monensin and nigericin. Monensin and nigericin treatments led to reduction of acid sphingomyelinase activity and disturbance of the esterification of lipoprotein-derived cholesterol in cultured fibroblasts, which is compatible with the biochemical changes of Niemann-Pick disease, type C. A23187, ionomycin, and lasalocid treatments showed only sphingomyelinase reduction in treated fibroblasts. Experimental models in this culture system could be produced in these ways, mimicking subtypes of Niemann-Pick disease, type A, B and type C.

Different regulation of plasminogen activator inhibitor 2 gene expression by phorbol ester and cAMP in human myeloid leukemia cell line PL-21

Previous studies have shown that protein kinase C (PKC) activators and dibutyryl cyclic AMP (Bt2cAMP) synergistically increase the antigen level of plasminogen activator inhibitor type-2 (PAI-2) in a human myeloid leukemia cell line PL-21. To clarify the mechanism, PAI-2 gene expression induced by phorbol myristate acetate (PMA), a PKC activator, and Bt2cAMP was investigated by Northern blot hybridization using a PAI-2 cDNA probe cloned from a human placental library. The level of PAI-2 mRNA was markedly increased in response to PMA and reached a maximum 5-9 h after stimulation. Nuclear run-on assay revealed an increase in PAI-2 gene transcription in PMA-treated cells. The induction was inhibited by inhibiting de novo protein synthesis with cycloheximide (CHX). cAMP also increased PAI-2 mRNA level in a dose-dependent manner. The increase began within 2 hours and, contrary to the case of PMA, the mRNA levels were maintained. Moreover, cAMP-induced increase in PAI-2 mRNA was not inhibited by CHX, rather enhanced. PMA and cAMP synergistically induced PAI-2 gene expression, which was completely inhibited by CHX. The cells pretreated with PMA for 24 h did not any more respond to stimulation with PMA but responded to cAMP and PAI-2 mRNA level was increased. The apparent half-life of constitutive level PAI-2 mRNA in PL-21 cells, determined by actinomycin-D-decay experiments, was approximately 2 h. Those induced by PMA and cAMP were approximately 5 h and 2 h, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

[Juvenile Parkinson's disease initially presenting as bulbar incoordination: a case report]

We report a case of juvenile Parkinson's disease which initially presented as bulbar incoordination at the age 12. The condition was characterized by dystonia of the upper extremities. The patient was a 14-year-old female. The patient's main symptoms were bulbar dysfunction. Resting and action tremor, akinesia, stooped posture, distortion of the trunk, dystonia of the upper extremities, oculogyric crisis, and impairment of the postural reflex were seen. The bulbar symptoms were considered to be attributable to circumoral uncoordination. Although L-dopa decarboxylase inhibitors were markedly effective in alleviating these symptoms, an adverse reaction due to the agent was observed as the form of oral dyskinesia. Since the changes in blood concentration of L-dopa after administration of the agent was clearly reflected in the surface electromyogram, we concluded that this diagnostic procedure is useful in evaluating the therapeutic efficacy of L-dopa.

[Genomic analysis of Japanese patients with adult-type metachromatic leukodystrophy]

We performed the genomic analysis of arylsulfatase A (ASA) gene in five Japanese patients with adult-type metachromatic leukodystrophy (MLD) including two sibling cases. Sequencing of amino acid coding region of ASA gene of proband case of family A disclosed 426Pro (CCG)-->Leu (CTG) mutation, which was reported to be frequently found in Caucasian patients with late-onset MLD. We developed mismatch primer PCR/RFLP method for detection of this mutation. If 426Pro-->Leu mutation exists in genomic DNA, Pst I site is newly created by PCR with a 3'-primer mismatched at one nucleotide. Genomic analysis of family A members using this method revealed that younger patient was homozygote of 426Pro-->Leu mutation and patient's parents and her younger brother were heterozygotes, which were confirmed by sequencing of exon 8 of ASA gene. Screening of this mutation using mismatch primer PCR/RFLP method was performed in one sibling case and one autopsy case. This point mutation was found in the sibling case. These results showed the possibility of world-wide spread of 426Pro-->Leu mutation in late-onset MLD patients and usefulness of our mismatch primer PCR/RFLP method for screening of this mutation.

Rapid detection of common mutation of arylsulfatase A in metachromatic leukodystrophy by polymerase chain reaction with a mismatched primer

The most common mutation in late-onset metachromatic leukodystrophy is a cytosine-to-thymine substitution in exon VIII. This mutation caused a substitution of leucine for proline at amino acid residue 426. We developed a rapid and simple method for the detection of 426Pro-->Leu mutation by polymerase chain reaction with mismatched primer. Although the 426Pro-->Leu mutation does not alter recognition sequence for restriction enzymes, we created a Pst I restriction site using a 3'-primer mismatched at one nucleotide. As a result, the mutation can be detected as a Pst I restriction fragment length polymorphism.

Clinical evaluation of low-molecular-weight heparin (FR-860) on disseminated intravascular coagulation (DIC)--a multicenter co-operative double-blind trial in comparison with heparin

This study was evaluated the effectiveness, safety and utility of FR-860 and to compare those with heparin in patients with Disseminated intravascular coagulation (DIC). A diagnosis of DIC was made based on the criteria proposed by the Research Committee on DIC in the Ministry of Health and Welfare of Japan. FR-860 (FR group, 75 anti-factor Xa international units/kg/day) and Heparin (HP group, 240 units/kg/day) were administered for 5 days by continuous intravenous infusion. The total number of enrolled patients was 126 cases, and after excluding 1 case a total of 125 cases. Moderate or higher improvement of bleeding symptoms was 33.3% in the FR group and 18.5% in the HP group. On the organic symptoms, FR group showed a significantly higher improvement rate than the HP group, 20.5% and 8.2% respectively. On the overall efficacy of cases with pretreatment plasma AT III levels of less than 21 mg/dl or less than 70%. FR group showed a significantly higher improvement rate than the HP group. The safety rate of FR-860 (93.4%) was a significantly higher than that of the HP group (79.7%). Our report demonstrates that FR-860, as a therapeutic agent for the treatment of patients with DIC, is significantly higher safety and clinical utility as compared with heparin.

Thrombospondin as an agglutinin of platelets

To study a hypothesis that thrombospondin (TSP) might function as an agglutinin in platelet aggregation, we designed two experiments. First, we prepared fibrinogen-coated agarose beads (fbg-beads) as a model of platelets, and subjected them to aggregometry using TSP as an inducer. TSP induced agglutination of fbg-beads in a dose-dependent manner. Calcium (Ca) and Magnesium (Mg) were necessary for the agglutination, and the aggregability was dependent on the concentration of Ca. These results confirmed the function of TSP as an agglutinin, suggesting some characteristics of the fbg-TSP interaction as well. Secondly, a variety of platelets were subjected to TSP-induced aggregation assay. Both gel-filtrated and washed-platelets were aggregated by TSP in a dose dependent manner and dissociated with EDTA. The same aggregation was observed in formalin-fixed platelets. Both Ca and Mg were required for the aggregation, and the maximum aggregation rate was dependent on the Ca concentration. Ca seemed to regulate the capacity as well as the affinity of the binding sites for TSP on platelets. Fibrinogen and some aminosugars inhibited the aggregation. These data suggest TSP may function as an agglutinin of platelets, and Ca may regulate the interaction between platelets and TSP. As one of the candidates for the receptor for TSP on platelet, fbg-GPIIb/IIIa was suggested because of the similarity between fbg-beads and platelets aggregation induced by TSP, and the Ca-dependency in both the GPIIb/IIIa induction and the TSP-induced platelet aggregation.